Scales

There are scales used for a number of physical phenomenon.

Do students need to be aware of these, and of the criteria for moving up through the levels of these scales? If so, which ones are the most important to know?

Fujita Scale (F-Scale) or Fujita Pearson (FPP-Scale) - Tornadoes

Also called the Enhanced Fujita (EF) Scale.

From F0-F5

The scale was introduced in 1971 by Ted Fujita of the University of Chicago, in collaboration with Allen Pearson, head of the National Severe Storms Forecast Center/NSSFC (currently the Storm Prediction Center/SPC). The scale was updated in 1973, taking into account path length and width.

Saffir-Simpson Hurricane Wind Speed Scale (SSHWS) - Hurricanes / Cyclones / Typhoons

From 1-5

Prior to this, storms will also be labelled as Tropical Depression (TD) and Tropical Storm (TS)

As sustained wind speeds intensify the storms move up through the scale. There have been suggestions that warmer oceans may necessitate the addition of a scale 6.

Hurricanes are also named, with a system for naming them based on pre-prepared lists, with the names of particularly devastating storms being 'retired'.

Beaufort Wind Force Scale - Wind speed

From 0-12

The scale was devised in 1805 by the Irish hydrographer Francis Beaufort (later Rear Admiral Sir Francis Beaufort), a Royal Navy officer while serving on HMS Woolwich, based on the work of others.

Major storms are now named by the Met Office, and other meteorological organisations.

(Gutenburg-)Richter magnitude scale - Earthquakes

From 1-9+ (no upper end)

The Richter scale – also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg-Richter scale – is a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 paper, where he called it the "magnitude scale". This was later revised and renamed the local magnitude scale, denoted as ML or ML .

Modified Mercalli Intensity Scale - MMI - Earthquakes

From I - XII

The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the effects of an earthquake at a given location, distinguished from the earthquake's inherent force or strength as measured by seismic magnitude scales

Volcanic Explosivity Index (VEI) - Volcanic eruptions

From 1-8 but open ended.

OK, an index rather than a scale...

The volcanic explosivity index (VEI) is a relative measure of the explosiveness of volcanic eruptions. It was devised by Chris Newhall of the United States Geological Survey and Stephen Self at the University of Hawaii in 1982.

Some scales are now in need of updating due to the changing climate.

The Australian bush fire danger rating system is being updated.

What other scales should students be aware of, and what misconceptions need to be tackled regarding their use?

Image: Weston's Fish Shop, Alan Parkinson - shared under CC license